Windows 7 PC intermittently shuts off without warning

[Eunos_Cosmo]

My PC is a few years old now (I built in 2013) and since like 2 weeks ago, the computer will shut off without warning (as if somebody pulled the AC cable) and I cannot seem to figure out what it is or repeatedly cause it to happen. Some things I've tried:

Different AC cable
Different outlet
Monitored & logged heat sensor levels (no peaks or anything pointing to overheating conditions prior to shut off)
Monitored voltage level at my surge protector (always between 119-122 volts)
Checked event reports (nothing interesting)

The weird thing is that it doesn't really happen for any obvious reason. I could be using the computer, or it could be sitting idle while I'm in another room, and then all of a sudden I'll here it booting back up again. I'm fairly certain it has something to do with voltage protection of the PSU because I noticed 2 things:

One time I plugged in a USB device and it automatically shut off
I tried plugging the AC cord directly into the wall socket and it shut off much more frequently.

As it is now, the computer will generally run fine for a few hours, and shut off without warning. The only time it didn't was as above when I plugged it directly into an outlet, and it seemed to happen more frequently. The wall outlets don't appear to be abnormal in their voltage output, so I'm really flumixed here.

I did notice one time I heard a "clicking noise" from near the PSU (sounded like a relay) followed immediately by a shut down. I've tried monitoring for under or over voltage, but I haven't really seen any smoking guns.

Any ideas?

Windows 7
Micro-atx mobo
Ivy bridge I7
32gb ddr3
Samsung SSD
1TB HDD
AMD Radeon 7800
Corsair 600W power supply

I haven't made any hardware or software changes in a long time.

 

[Black Z Eddie]

My first instinct is it could be the PSU or the MB going bad.

Another, is I had a similar issue years and years ago. I had brand new components. I somehow figured out it was the CPU voltage. I lowered it just a notch or two from the default and the problem went away. So something wasn't cooperating between the PSU, CPU, and MB.

 

[MXM]

Which mobo? My old Asus on Z77 did exactly that, usually cold reboots, sometimes BSOD, sometimes triggered by some action, often just when idling. I've tried swapping pretty much every other component before finally swapping the mobo, and that fixed everything.

 

[thevictor390]

In my experience you will find out soon enough when the component finally fails..... PSU or motherboard seem to be the obvious possibilities.

 

[mpicco]

My first instinct is it could be the PSU or the MB going bad.

Another, is I had a similar issue years and years ago. I had brand new components. I somehow figured out it was the CPU voltage. I lowered it just a notch or two from the default and the problem went away. So something wasn't cooperating between the PSU, CPU, and MB.

Was my first thought too.

Worse scenario: motherboard starting to fail

 

[Eunos_Cosmo]

Is there any risk to the CPU or GPU in continuing to use the computer if the PSU or Mobo takes a crap?

 

[SidS1045]

Are all the fans running as they should?

When was the last time you blew the dust out of it? Computers tend to attract dust like a magnet.

 

[Blayde]

try a fresh install of win7 first? i had a weird boot issue that i assumed was hardware, but a fresh reinstall fixed it

 

[73GMCSprint]

This was a year ago guys.

 

[Blayde]

woops, my bad